1. Cut a small slice lengthwise along the courgettes and scoop out a little of the flesh and chop it finely.
2. Blanch the courgettes for 2 minutes in boiling salted water.
3. Add the shrimps or prawns, chopped egg and chopped courgette to the Bechamel Sauce.
4. Fill the courgettes with the mixture and sprinkle with Parmesan cheese.
5. Bake at 180°C (350°F) Gas 4 for 15 - 20 minutes.